United Nations Secretary-General Ban Ki-moon says a deal to reunite the divided island of Cyprus is "within reach" as he opens talks in Switzerland.

Ban said the five-day negotiations between Greek Cypriot President Nicos Anastasiades and his Turkish Cypriot counterpart, Mustafa Akinci, will focus on the issue of territory and "other outstanding issues."

"The prospect of a solution in Cyprus is within their reach. Expectations in both communities are high," he told reporters on November 7.

Nicosia has been at loggerheads with Turkey since a 1974 Turkish invasion partitioned the island into two sectors, the Greek Cypriot side recognized internationally as Cyprus, and a breakaway Turkish Cypriot state.

The northern Cyprus state is recognized only by Turkey and subject to international sanctions.

The recent discovery of natural-gas reserves off the island's coast has raised the stakes in any peace deal.